General purpose: To investigate schizophrenic-normal differences in autonomic nervous system activity in various laboratory situations which differ in the demands placed on the subject, the kinds of stimuli presented and the type of behavior required. To determine biological and psychological processes related to ANS activity. Peripheral measures of autonomic functioning: Skin conductance, heart rate, finger pulse volume, respiration and skin temperature are recorded continuously during periods of resting, presentation of mild tones and task performance. The tasks used include reaction time, mental arithmetic, two-flash threshold, and tachistoscopic recognition. We showed that drug free acute schizophrenics who did not improve during a subsequent 4 months hospitalization were more deviant in ANS functioning at admission than were patients who improved. Current studies aim to replicate and extend this finding in patients who are on controlled drug trials to see if on or off drug ANS activity is related to therapeutic outcome. BIBLIOGRAPHIC REFERENCES: Zahn, T.P. Autonimic nervous system characteristics possibly related to a genetic predisposition to schizophrenia. Schizophrenia Bulletin 3: 49-60, 1977. Zahn, T.P. Autonomic system characteristics possibly related to a genetic predisposition to schizophrenia. Schizophrenia Bulletin 3: 49-60, 1977.